iphone - Why is animationDidStart called after removeAllAnimations is called? -

in animationdidstart (cabasicanimation delegate), want update catextlayer. however, if user touches screen, want remove animations going on [self.masklayer removeallanimations]; (all animations played sequentially).

however, after removeallanimations, somehow, animationdidstart , animationdidstop still called, animation not shown. not want, obviously.

the animations added follows:

- (void)addanimations {  (int i=1; i<6; i++) { nsstring* intvalue = [nsstring stringwithformat:@"%d", i];  cabasicanimation *animation = [cabasicanimation animationwithkeypath:@"path"];  animation.duration = 0.5;  animation.delegate = self;  animation.repeatcount = 0;  animation.autoreverses = no;  [animation setvalue:intvalue forkey:@"animationstring"];  animation.timingfunction = nil;  [animation setremovedoncompletion:no];  [animation setfillmode:kcafillmodeforwards];  animation.fromvalue = (id) [self getcgrectforzoomlevel:i];  animation.tovalue = (id) [self getcgrectforzoomlevel:i + 1 ];  animation.begintime = cacurrentmediatime() + * 2;  [self.shapelayer addanimation:animation forkey:intvalue]; } } 

how prevent this? issue has taken me several hours :(

thanks!